The invention relates to a cooling module composed of at least a first and a second heat exchanger, which are connected in a common frame or directly with one another, and wherein cooling air can flow through both heat exchangers. The second heat exchanger has a greater structural depth than the first heat exchanger in the flow direction of the cooling air.
A cooling module of the above-mentioned type is known, for example, from German Published Patent Application DE 10 2010 011 495 A1. From this document, on which the present invention is based, a cooling module for motor vehicles is known which has several module elements. In this case, at least a first module element and a second module element are provided in the deformation area of the motor vehicle. The module element is characterized in that at least a first module element can be displaced with respect to the at least second module element.
For SULEV (Super Ultra Low Emission Vehicle) licenses in the automobile industry, up to now, exclusively a single heat exchanger—the coolant cooler—with a “PremAir®” coating (BASF Co.) had been surface-coated in a catalytically effective manner. PremAir® is the name of a system for converting ground-level ozone (triatomic oxygen molecules) to oxygen (biatomic oxygen molecules), installed, for example, by Volvo between 1998 and 2005. For this purpose, the cooler was provided with the above-mentioned catalytic PremAir® coating, which splits the ozone molecules. The free oxygen radicals will then combine again to form oxygen molecules (O2).
On the basis of the U.S. legal requirements of the EPA (Environmental Protection Agency) or of the CARB (California Air Resources Board), in this case, a maximal credit of 5 mg NMOG) (unburned hydrocarbons) can be reached for so-called DOR systems (Direct Ozone Reduction) when the DOR system directly converts ozone to oxygen and its function is continuously checked and protected from manipulation attempts by way of the OBD (onboard diagnosis in the vehicle).
In view of increasingly compact installation spaces and further increasing safety demands in vehicles, such as passive pedestrian protection systems for the front end of the vehicle, the front face of the heat exchangers or of the coolant cooler is reduced for newly developed vehicles such that achieving the maximally legally possible NMOG credit goal encounters its physical limits. The value of the NMOG credit to be entered is calculated from, among other things, the front face of the coated heat exchanger surface as well as the ozone conversion rate. When the two latter parameters are enlarged, the NMOG credit that can be obtained will increase. An assembled cooling module contains at least one additional heat exchanger that can be coated, such as a charge air cooler. Because of the larger overall depth, for example, of a charge air cooler, a functionally effective through-coating by means of a PremAir® coating according to the current industry standard cannot be achieved, and thus obtaining the additional NMOG credits is not possible.
It is an object of the present invention to provide a measure for avoiding the above-mentioned disadvantages.
This and other objects are achieved by a cooling module composed of at least a first and a second heat exchanger, which are connected in a common frame or directly with one another, and wherein cooling air can flow through both heat exchangers. The second heat exchanger has a greater structural depth than the first heat exchanger in the flow direction of the cooling air. The first and the second heat exchanger have a catalytic coating. The second heat exchanger is composed of at least one first and one second partial (component) heat exchanger which are arranged one behind the other in the flow direction of the cooling air and which are operatively connected with one another.
According to the invention, it is therefore provided that at least the second heat exchanger is designed such that, before final assembly, its block-type heat exchanger networks/-partial networks, can be through-coated in smaller or thinner units. This can be implemented by a block-type construction of the heat exchanger matrix which, after assembly, then resembles the final system depth. As a result, the objective of maximally possible NMOG credits can be achieved in the manner of emission credits. The reaching of the objective is therefore also ensured for future new projects with very tight installation space conditions. Advantageously, the further development according to the invention additionally results in a stability increase with respect to the aging of the coating because of the enlargement of the coated heat exchanger surface.
Preferably, the at least two partial (component) heat exchangers can be coated with the catalytic coating separately from one another in order to obtain, if possible, 100% surface coating and thereby an optimal efficiency.
In a preferred embodiment, the first heat exchanger is a radiator for an internal-combustion engine or, in a second embodiment, a condenser for a vehicle air-conditioning system.
The second heat exchanger preferably is a charge-air cooler or an exhaust gas recirculation cooler, which both have a relatively deep construction, or a low-temperature cooler, for example, for hybrid vehicles.
In a further, particularly preferred embodiment, a fluid to be cooled can flow in parallel through the at least two partial heat exchangers, and in a further embodiment, the fluid to be cooled can flow serially, i.e. successively, through the at least two partial heat exchangers.
In a particularly preferred U.S. embodiment, the first and the second heat exchanger are non-detachably mutually connected with the frame, so that a further OBD sensor for monitoring the conversion of ozone to oxygen will not be necessary. For this purpose, the first and the second heat exchanger are preferably mutually connected with the frame in a firmly bonded and/or form-fitting manner in a way that attempted disassembling of them would lead to damage to the heat exchanger.
A catalytic coating is used as a preferred coating, which catalytic coating splits the ozone molecules consisting of three oxygen atoms into oxygen molecules consisting of two oxygen atoms.
The cooling module according to the invention is particularly preferably used in motor vehicles and airplanes.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of one or more preferred embodiments when considered in conjunction with the accompanying drawings.